. "thick, dense , i. e. consisting of parts crowded together. opp. to rarus (on the contrary, crassus, thick , is opp. to thin, fluid ; and spissus, close, compact" . "thick, dense , i. e. consisting of parts crowded together. opp. to rarus (on the contrary, crassus, thick , is opp. to thin, fluid ; and spissus, close, compact" . .